This invention relates generally to the field of integrated circuits and more specifically to a method and system for mask pattern correction.
Masks such as photomasks are typically used in photolithographic systems to define patterns on objects such as integrated circuits. The shape of the mask, however, may sometimes differ from the pattern defined on the object. For example, optical diffraction may cause a resulting pattern defined on an integrated circuit to differ from the shapes on the mask. Consequently, masks are typically adjusted to account for these deviations.
In accordance with the present invention, a method and system for mask pattern correction are provided that substantially eliminate or reduce the disadvantages and problems associated with previously developed systems and methods.
According to one embodiment of the present invention, a method for mask pattern correction is disclosed. A portion of a mask pattern is segmented into segments that include at least one base segment and at least one relational segment. Each relational segment is matched with a base segment. A proximity correction is determined for each base segment. A critical dimension correction is determined for each relational segment. The critical dimension correction is determined with respect to the proximity correction of the matching base segment. Each base segment is adjusted according to the proximity correction, and each relational segment is adjusted according to the critical dimension correction.
Embodiments of the invention may provide numerous technical advantages. A technical advantage of one embodiment may be that a segment of a mask pattern is corrected with respect to an already corrected segment of the mask pattern. By correcting one segment with respect to another segment, a critical dimension defined by the segments may be more readily achieved. Another technical advantage of one embodiment may be that segments that define a critical dimension may be matched, and the matching may be recorded in a record associated with one of the segments. The record may be used to retrieve the corrected position of one segment in order to correct the position of the other segment. Another technical advantage of one embodiment may be that a number of provisional corrections may be used to simultaneously represent the positions of the segments. The correction bars of matched segments may be used to determine a correction for a segment.
Other technical advantages are readily apparent to one skilled in the art from the following figures, descriptions, and claims.